基于碳点电化学和电致化学发光乙酰胆碱传感器研究

发布时间：2018-07-07 17:37

本文选题：碳点 + 层状双金属氢氧化物　；参考：《北京化工大学》2016年博士论文

【摘要】：碳点是一种粒径小于10 nm的碳纳米晶,由于具有良好的生物相容性和低毒性、良好的水溶性、很好的化学惰性、抗光漂白性以及可调的带隙等优点,作为碳纳米家族的一颗新星,引起了人们的广泛关注。尤其是碳点具备独特的光学和电化学性质,在传感、光电子、生物医药和电催化等领域具有潜在的应用。乙酰胆碱,作为一种研究最为普遍的神经递质,在中枢和外周神经系统起着神经传导的作用。乙酰胆碱在多种生命过程中,如学习、记忆、情感和运动等,都起到了重要的作用。因此,神经系统中乙酰胆碱的检测十分重要。另外,乙酰胆碱不仅存在于神经系统中,而且普遍存在于一切活细胞中,包括上皮细胞、内皮细胞、免疫细胞等,这些细胞中合成的乙酰胆碱属于非神经性乙酰胆碱系统。在非神经性乙酰胆碱系统中,乙酰胆碱可以调节不依赖神经的细胞功能,如增殖、分化、细胞骨架构建、运动、分泌、鞭毛活动和局部释放调节等。然而,非神经性乙酰胆碱系统中,乙酰胆碱的含量非常低,为pmol L-1级。因此,非神经性乙酰胆碱系统中乙酰胆碱的检测不仅非常重要,而且还是一项具有很大挑战性的工作。在本论文研究中,我们开发了一种新的制备碳点的方法,并利用碳点/层状双金属氢氧化物复合物和碳点/阳离子二肽纳米囊泡复合物分别构筑乙酰胆碱电化学和电致化学发光生物传感器。具体工作如下：1、高能球磨法制备碳点利用高能球磨活性炭和氢氧化钾的混合物,再经过超滤纯化的方法制备了具有丰富表面态的碳点。所制备的碳点展现了双波长荧光性质。进一步研究表明,第一个发射峰与表面含氧官能团数量有关,且不随激发波长的移动而移动；第二个发射峰与碳点的粒径有关,且随着激发波长的增加单调红移。同时,所制备的碳点也展现了双波长电致化学发光性质。2、基于碳点修饰花状镍铝层状双金属氢氧化物构筑无酶乙酰胆碱传感器利用水热方法合成了由纳米片交叉连接构成的高比表面积花状镍铝层状双金属氢氧化物,之后,将带有负电荷的碳点修饰到镍铝层状双金属氢氧化物表面而获得镍铝层状双金属氢氧化物/碳点复合物。与纯的镍铝层状双金属氢氧化物相对比,镍铝层状双金属氢氧化物/碳点复合物展现了更好的导电性和电催化氧化乙酰胆碱的能力。此镍铝层状双金属氢氧化物/碳点复合物修饰的玻碳电极对乙酰胆碱的检测具有宽的线性范围(5-6885μmoL-1),高的灵敏度(133.20±0.03mAM-1cm-2)和低的检测限(1.7μmol L-1)。同时,此生物传感器还表现出了良好的耐久性和长期稳定性,以及非常好的选择性。这些优异的性能要归功于镍铝层状双金属氢氧化物和碳点之间的协同作用：由纳米片交叉连接构成的高比表面积花状镍铝层状双金属氢氧化物有效地提高电极与电解液的接触面积,从而加快了反应动力学；带有负电荷的碳点修饰在带有正电荷的层状双金属氢氧化物的层板上,提高了镍铝层状双金属氢氧化物/碳点复合物的导电性,生物相容性以及对乙酰胆碱的亲和力。3、基于阳离子二肽纳米囊泡/碳点复合物构筑乙酰胆碱电致化学发光传感器利用阳离子二肽纳米管向阳离子二肽纳米囊泡的微结构转变,将单分散的碳点嵌入到阳离子二肽纳米囊泡壁内形成阳离子二肽纳米囊泡/碳点复合物。此复合物具有良好的生物相容性,结构稳定性以及由于二肽纳米囊泡和碳点双电致发光体之间的协同作用而产生的稳定而强烈的电致化学发光信号。此阳离子二肽纳米囊泡/碳点复合物修饰电极可以用于乙酰胆碱超灵敏检测,检测限可低至2.4 pmol L-1(信噪比为3),同时,此体系还具有很好的选择性和长期稳定性。此优异的性能要归功于阳离子二肽纳米囊泡和碳点之间的协同作用：带阴离子表面电荷的碳点嵌入到阳离子二肽纳米囊泡内,形成稳定的结构；二肽纳米囊泡和碳点形成复合物,使电致化学发光的路径增加；二肽纳米囊泡和碳点都对乙酰胆碱具有很好的选择性。这种具有协同作用的纳米复合材料将在生物传感器、生物成像、生物药物、生物电子、生物催化和生物能源等领域具有广阔的应用前景。
[Abstract]:Carbon point is a carbon nanocrystalline with a particle size less than 10 nm. Due to its good biocompatibility and low toxicity, good water solubility, good chemical inertness, anti photobleaching and adjustable band gap, it has attracted wide attention as a new star of carbon nanofamily. Especially, carbon points have unique optics and electrification. It has potential applications in the fields of sensing, photoelectrons, biopharmaceutical and electrocatalysis. Acetylcholine, as one of the most common neurotransmitters, plays the role of nerve conduction in the central and peripheral nervous systems. Acetylcholine plays an important role in a variety of life processes, such as learning, memory, emotion, and exercise. Therefore, the detection of acetylcholine in the nervous system is very important. In addition, acetylcholine exists not only in the nervous system but also in all living cells, including epithelial cells, endothelial cells, immune cells and so on. The acetylcholine in these cells is a non neurogenic acetylcholine system. In non neurogenic acetylcholine. In the system, acetylcholine can regulate the function of cells that do not depend on the nerve, such as proliferation, differentiation, cytoskeleton construction, movement, secretion, flagellum activity and local release regulation. However, the content of acetylcholine in non neurogenic acetylcholine system is very low, pmol L-1. Therefore, the assay of acetylcholine in non neurogenic acetylcholine system Measurement is not only very important, but also a very challenging task. In this paper, we developed a new method of preparing carbon points, and constructed acetylcholine electrochemiluminescence and electrochemiluminescence using carbon point / layered double metal hydroxide complex and carbon point / cationic two peptide Nanovesicles. The specific work is as follows: 1, a high energy ball milling method is used to prepare a mixture of activated carbon and potassium hydroxide with high energy ball milling, and then a rich surface state carbon point is prepared by ultrafiltration. The carbon points prepared have shown the dual wavelength fluorescence properties. Further research shows that the first emission peak and the surface oxygen functional energy have been shown. The number of clusters is related and does not move with the movement of the excitation wavelengths; the second emission peaks are related to the particle size of the carbon point and monotonically red shift with the increase of the excitation wavelengths. At the same time, the prepared carbon points also exhibit a double wavelength electrochemiluminescence property.2, based on the carbon point modification of the flower like nickel aluminum layered double metal hydroxide to construct an enzyme free acetylcholine. The sensor uses a hydrothermal method to synthesize a high specific surface area flower like nickel aluminum layered double metal hydroxide formed by the cross connection of nanoscale. After that, the negative charge carbon point is modified to the surface of the nickel aluminum layered double metal hydroxide, and the nickel aluminum layered double metal hydroxide / carbon point complex is obtained. The nickel aluminum layered double metal hydroxide / carbon point complex showed better conductivity and electrocatalytic oxidation of acetylcholine. The nickel aluminum layered double metal hydroxide / carbon point composite modified glassy carbon electrode has a wide linear peri (5-6885 moL-1) and high sensitivity (133.20 + 0) for the detection of acetylcholine. 3mAM-1cm-2) and low detection limit (1.7 Mu mol L-1). At the same time, the biosensor also shows good durability and long-term stability, and very good selectivity. These excellent properties are due to the synergism between the nickel aluminum layered double metal hydroxide and the carbon point: high specific surface area made up of nanoscale cross connections. Nickel aluminum layered double metal hydroxide improves the contact area of the electrode and the electrolyte, and thus accelerates the reaction kinetics, and the negative charge carbon point is modified on the laminates with positive charged layered double metal hydroxide, which improves the conductivity of the nickel aluminum layered double metal hydroxide / carbon point complex. The affinity.3 of acetylcholine, based on the cationic two peptide nano vesicle / carbon point complex to construct the electrochemiluminescence sensor of acetylcholine, uses the microstructural transformation of cationic two peptide nanotube to the cationic two peptide nanoscale, and the monodisperse carbon points are embedded into the cationic two peptide nanoscale wall to form a cationic two peptide nanoscale. This complex has good biocompatibility, structural stability and a stable and strong electrochemiluminescence signal produced by the synergistic effect of two peptide nanoscale and carbon point double electroluminescent bodies. This cationic two peptide nano vesicle / carbon point complex modified electrode can be used for acetylcholine hyper Sensitive detection, the detection limit can be as low as 2.4 pmol L-1 (signal-to-noise ratio 3). At the same time, the system also has good selectivity and long-term stability. The excellent performance is due to the synergism between the nano vesicles of the cationic two peptide and the carbon point: the carbon point with the surface charge of the anion is embedded into the cationic two peptide nanoscale to form a stable junction. The two peptide Nanovesicles and carbon dots form complex to increase the path of electrochemiluminescence; the two peptide nanoscale and carbon dots have good selectivity to acetylcholine. This synergistic nanocomposite will be used in biosensors, bioimaging, Bioelectronics, Bioelectronics, biocatalysis and bioenergy. The domain has a broad application prospect.
【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O613.71;TP212.3

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